//
// NamedSemaphore.h ,Posix Style
//
// $Id: //poco/1.4/Foundation/include/Poco/NamedSemaphore.h#2 $
//
// Library: Foundation
// Package: Processes
// Module:  NamedSemaphore
//
// Definition of the NamedSemaphore class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_NamedSemaphore_INCLUDED
#define Foundation_NamedSemaphore_INCLUDED


#include "Poco/Foundation.h"

#if defined(POCO_OS_FAMILY_UNIX)
#include "Poco/NamedSemaphore_UNIX.h"
#endif


namespace Poco {


class Foundation_API NamedSemaphore: public NamedSemaphoreImpl
	/// An NamedSemaphore is a global synchronization object 
	/// that allows one process or thread to signal an
	/// other process or thread that a certain event
	/// has happened.
	///
	/// Unlike an Event, which itself is the unit of synchronization,
	/// a NamedSemaphore refers to a named operating system resource being the
	/// unit of synchronization.
	/// In other words, there can be multiple instances of NamedSemaphore referring
	/// to the same actual synchronization object.
	///
	/// NamedEvents are always autoresetting.
	///
	/// There should not be more than one instance of NamedSemaphore for
	/// a given name in a process. Otherwise, the instances may
	/// interfere with each other.
{
public:
	NamedSemaphore(const std::string& name);
		/// Creates the event.
		
	~NamedSemaphore();
		/// Destroys the event.

	void set();
		/// Signals the event. 
		/// The one thread or process waiting for the event 
		/// can resume execution.

	void wait();
		/// Waits for the event to become signalled.

	bool tryWait();
		/// true: success, false fail
	
	bool tryWait(long milliseconds); 
		/// true: success, false fail
private:
	NamedSemaphore();
	NamedSemaphore(const NamedSemaphore&);
	NamedSemaphore& operator = (const NamedSemaphore&);
};


//
// inlines
//
inline void NamedSemaphore::set()
{
	setImpl();
}


inline void NamedSemaphore::wait()
{
	waitImpl();
}

inline bool NamedSemaphore::tryWait()
{
	return tryWaitImpl();
}


inline bool NamedSemaphore::tryWait(long milliseconds)
{
	return tryWaitImpl(milliseconds);
}

} // namespace Poco


#endif // Foundation_NamedSemaphore_INCLUDED
